Diazotype development apparatus



Aug. 25, 1964 F. H. FRANTZ DIAZOTYPE DEVELOPMENT APPARATUS Filed July 12, 1960 INVENT FREDERICK Ii. FHA

United States Patent 3,145,637 DIAZOTYPE DEVELOPMENT APPARATUS Frederick H. Frantz, Binghamton, N.Y., assignor to General Aniline & Film Corporation, New York, N.Y., a corporation of Delaware Filed July 12, 1960, Ser. No. 42,369 1 Claim. (Cl. 95-94) This invention relates to a process and apparatus for developing and drying diazotype material. More particularly, this invention relates to the moist development and drying of diazotype paper of the one component type, wherein the paper is coated with a light sensitive diazo compound, exposed and then developed with a solution containing a coupling component.

In the known moist process of developing and drying diazotype material, the developing solution is first applied to the exposed paper and then dried by conveying the paper over or past heating elements such as infrared lamps, heated tubular steel rods or resistance wire. It was found, however, that if the paper is held flat while being dried, it loses its flat and smooth surface and acquires a tendency to curl after drying.

It is an object of this invention to provide a novel process and apparatus for moist developing and drying diazotype paper which will eliminate the tendency to curl after the paper is dried.

It is another object of this invention to provide a novel process and apparatus for developing and drying a diazotype paper which process is continuous and produces a print which is flat and has a smooth surface.

Other objects and advantages of this invention will appear to those skilled in the art from the detailed description thereof given below when taken in connection with the accompanying drawing in which:

FIGURE 1 is a perspective view, partly in section, of one form of an apparatus which may be used to practice my novel method; and

FIGURE 2 is a side view thereof.

In the drawing, 1 and 2 are trays or tanks for holding the developing solution which preferably contains a coupling component, 3 and 4 are transfer rollers dipping into the solution and 5 and 6 are applicator rollers which contact the transfer rollers 3 and 4 and the exposed sheet of diazotype paper 7 passing between rollers 5 and 6. With the construction shown, the developing solution is uniformly applied to both sides of the paper. After the developing solution is thus applied, the paper is dried.

The drying mechanism comprises two sets of rollers 8, 9 and 10, 11. The rollers 8 and 9 are vertically spaced, but in alignment with each other as are also rollers 10 and 11. Rollers 8 and 10 and rollers 9 and 11 are closely spaced and are disposed in side by side parallel relation above rollers 5 and 6 and so positioned that the bite between the two sets of rollers and the bite between rollers 5 and 6 are in substantial aligment.

Rollers 8 and 9 carry an endless belt 12 and rollers 10 and 11 carry an endless belt 13. Means (not shown) are provided for rotating the various rollers in the direction shown by the arrows.

Each of the belts 12 and 13 forms a chamber between the two runs thereof. These chambers are designated 14 and 15. Stationary heating elements 16 and 17 are posi- 3,145,637. Patented Aug. 25, 1964 tioned within these chambers for the purpose of furnishing the heat for drying the paper. These heating ele ments may be of any desired type as, for example, infrared lamps, resistance elements or metal pipes for conveying steam or other heated fluid.

Positioned within the chamber 14 to contact the inner surface of the side of the belt in contact with paper 7 is a stationary, rigid, curved and perforated plate 18. The plate 18 is so positioned as to force the side of the belt in contact with paper 7 out of alignment with the bite between rollers 8 and 10 which causes a pressing of the paper 7 against belts 12 and 13.

The paper 7 as it leaves the top of the belts is deposited in tray 19.

In operation, exposed diazotype paper 7 is inserted between applicator rollers 5 and 6. Rotation of transfer rollers 3 and 4 transfers a film of developing solution to applicator rollers 5 and 6 which rollers apply the film of solution to both sides of paper 7. From the applicator rollers, the paper is conveyed between belts 12 and 13 which also move the paper out of the device and into tray 19. In moving past chambers 14 and 15, the paper is dried by the heat from the heating elements and pressed or ironed and curved by the belts as they move past the plate 18. The paper issuing from between the belts and deposited in tray 19 is dry, flat and has a smooth surface. The paper has no tendency to curl primarily due to the fact that the solution is applied uniformly to both surfaces of the paper and due to the pressure and curvature which is applied to the paper while drying.

Modifications may be resorted to within the scope of the appended claim.

I claim:

An apparatus for developing and drying diazotype paper comprising two elongated trays, adapted to contain a liquid, positioned side by side in spaced relation to each other, a transfer roller positioned in each tray and adapted to be partially immersed in the liquid, an applicator roller positioned parallel to each transfer roller and in contact therewith, two sets of adjacent parallel rotatable rollers vertically spaced and positioned with both the bites between the two sets of rollers in substantial alignment with the bite between the two applicator rollers, an endless belt supported and moved by each set of said two sets of rollers, stationary heating means positioned in the space between the two runs of each belt to heat said paper as it is being moved by the belts and an arcuately curved plate positioned to press against the run of one of the belts which is in contact with said paper to press the paper between the two belts and to impart a curvature to said paper while it is being dried.

References Cited in the file of this patent UNITED STATES PATENTS 2,257,207 Von Melster Sept. 30, 1941 2,328,781 Brunk Sept. 7, 1943 2,333,733 Morse Nov. 9, 1943 2,437,254 Hill Mar. 9, 1948 2,776,888 Pop Jan. 8, 1957 2,789,904 Benbrook et a1. Apr. 23, 1957 2,792,700 Altosaar May 21, 1957 2,981,171 Hruby et al Apr. 25, 1961 3,000,287 Heldens Sept. 19, 1961 

